Environmental monitoring, sensing and measurements have become of interest to enterprises and individuals wishing to assess the current conditions of the environment in which individuals live or work or to characterize and monitor the quality of the environment. In some cases, environmental monitoring is performed to establish trends in environmental parameters, such as for detecting operations of building heating and cooling systems or operation of factory machinery. In other cases, environmental monitoring may be performed for detecting climate changes. Environment sensing and measurements can include air quality monitoring, water quality monitoring, and monitoring of other environment factors.
Air quality is a measure of the condition of air relative to the requirements of human need or purpose. Outdoor air quality monitoring is performed to measure the levels of pollutants in the air so as to detect potential harmful air pollution. Outdoor air quality monitoring is typically carried out using monitoring station installations in various physical locations. These monitoring stations measure the presence of contaminants in the air, such as carbon monoxide, ozone, particulate matter, sulphur dioxide (SO2) and carbon dioxide (CO2). Indoor air quality monitoring is becoming a matter of interest as the air in enclosed spaces, such as home, schools or workplaces, can also be polluted. Conventional air quality monitors are expensive and require complex calibration procedure to ensure accurate measurements.